Human hair becomes soiled due to its contact with the surrounding atmosphere and, to a greater extent, from sebum secreted by the head. The build-up of the sebum causes the hair to have a dirty feel and an unattractive appearance. The soiling of the hair necessitates it being shampooed with frequent regularity.
Shampooing the hair cleans by removing excess soil and sebum. However, the shampooing process has disadvantages in that the hair is left in a wet, tangled and generally unmanageable state. Shampooing can also result in the hair becoming dry or "frizzy", and a loss of luster, due to removal of natural oils or other hair moisturizing materials. After shampooing, the hair can also suffer from a loss of "softness" perceived by the user upon drying. The hair can also suffer from increased levels of static upon drying after shampooing. This can interfere with combing and can result in fly-away hair. A variety of approaches have been developed to alleviate the after-shampoo problems. These range from the inclusion of hair conditioning aids in shampoos to post-shampoo application of hair conditioners, i.e., hair rinses. Hair rinses are generally liquid in nature and must be applied in a separate step following the shampooing, left on the hair for a length of time, and rinsed with fresh water. This, of course, is time consuming and is not as convenient as shampoos containing both cleaning and hair conditioning ingredients.
While a wide variety of shampoos have been disclosed which contain conditioning aids, they have not been totally satisfactory for a variety of reasons. Cationic conditioning agents are highly desirable for use in hair conditioning due to their abilities to control static, improve wet detangling, and provide a silky wet hair feel to the user. One problem which has been encountered in shampoos relates to compatibility problems between good cleaning anionic surfactants and the many conventional cationic agents which historically have been used as conditioning agents. Efforts have been made to minimize adverse interaction through the use of alternate surfactants and improved cationic conditioning agents. Cationic surfactants which provide good overall conditioning in hair rinse products, in general, tend to complex with anionic cleaning surfactants and provide poor conditioning in a shampoo context. In particular, the use of soluble cationic surfactants that form soluble ionic complexes do not deposit well on the hair. Soluble cationic surfactants that form insoluble ionic complexes deposit on the hair but do not provide good hair conditioning benefits, and tend to cause the hair to have a dirty, coated feel. The use of insoluble cationic surfactants, e.g., tricetyl methyl ammonium chloride, can provide excellent anti-static benefits but do not otherwise provide good overall conditioning. Many cationic polymers tend to build up on the hair, resulting in an undesirable, "unclean" coated feel. Cationic polymers therefore, conventionally, are preferably used at limited levels to minimize this problem. This, however, can limit the overall conditioning benefits that are obtained. Additionally, cationic conditioning agents commonly do not provide optimal overall conditioning benefits, particularly in the area of "softness", especially when delivered as an ingredient in a shampoo composition.
Materials which can provide increased softness are nonionic silicones. Silicones in shampoo compositions have been disclosed in a number of different publications. Such publications include U.S. Pat. No. 2,826,551, Geen, issued Mar. 11, 1958; U.S. Pat. No. 3,964,500, Drakoff, issued Jun. 22, 1976; U.S. Pat. No. 4,364,837, Pader, issued Dec. 21, 1982; and British Patent 849,433, Woolston, issued Sep. 28, 1960. While these patents disclose silicone containing compositions, they also did not provide a totally satisfactory product in that it was difficult to maintain the silicone well dispersed and suspended in the product. Recently, stable, insoluble silicone-containing hair conditioning shampoo compositions have been described in U.S. Pat. No. 4,741,855, Grote and Russell, issued May 3, 1988 and U.S. Pat. No. 4,788,066, Bolich and Williams, issued Nov. 29, 1988. These shampoo compositions can deliver excellent overall conditioning benefits to the hair while maintaining excellent cleaning performance, even with the use of anionic detersive surfactants, for a wide variety of hair types.
More recently, improved conditioning shampoos were provided in U.S. Ser. No. 07/622,699, Robert L. Wells, filed Dec. 5, 1990, now abandoned, and its continuation application Ser. No. 07/778,765, filed Oct. 21, 1991, wherein shampoos containing anionic surfactant, dispersed, insoluble silicone, and certain relatively low ionic strength cationic polymers (greater than about 0.4 meq./gm) were disclosed. These compositions provide excellent hair cleaning and conditioning to a wide variety of hair types, especially including improved conditioning to hair damaged by color treatments, bleaching, permanents, etc.
Japanese Patent Application, Laid Open No. 56-72095, Jun. 16, 1981, Hirota et al. (Kao Soap Corp.) also discloses shampoo containing cationic polymer and silicone conditioning agents. Still other patent publications relating to shampoos with cationic agents and silicone include EPO Application Publication 0 413 417, published Feb. 20, 1991, Hartnett et al.
Another approach to providing hair conditioning benefits to shampoo compositions has been to use materials which are oily to the touch. These materials provide improved luster and shine to the hair. Oily materials have also been combined with cationic materials in the shampoo formulations. Japanese Patent Application Showa 53-35902, laid open October 6, 1979 (Showa 54-129135), N. Uchino (Lion Yushi Co.), discloses hair treatment compositions containing cationic polymer, fatty acid salt, and at least 10% of an oily component for use before or after shampooing. Suitable oily components are hydrocarbons, higher alcohols, fatty acid esters, glycerides, and fatty acids. Japanese Patent Application 62 [1987]-327266, filed Dec. 25, 1987, published Jul. 4, 1989, laid open No. HEI 1[1987]-168612, Horie et al., discloses detergent compositions containing cationic surfactant and/or cationic polymer, anionic surfactant, and specific esters of the formula RCOOR' wherein R and R' are straight or branched chain alkyls.
In spite of these attempts to provide optimal combinations of cleaning ability and hair conditioning, there remains a need for personal cleansing compositions providing improved lathering and conditioning benefits. The present inventor has found that compositions combining certain nonionic or anionic polymers in combination with surfactants and a minimum level of a phase separation initiator form stable aqueous emulsions--wherein the emulsion comprises aqueous polymer phase droplets suspended in an aqueous surfactant phase. The dispersed, concentrated polymer phase provides improved hair and skin conditioning without sacrificing clean feel. These compositions can be made into any of a number of conventional forms including, but not limited to, conditioning shampoos, foams, mousses, gels, lotions, sprays and the like.
In addition to the afore-mentioned hair care benefits, it has been found that the nonionic or anionic polymer and surfactant system emulsion of the present invention is also useful for incorporation into a wide variety of personal skin cleansing compositions or used in conjunction with lathering instruments. These compositions provide a skin conditioning component which is more easily and uniformly deposited upon the skin and feel good upon the skin. Such compositions include liquid soaps, shower gels, lotions and the like. Suitable lathering instruments include nonwoven substrates, woven substrates, hydroentangled substrates, air entangled substrates, natural sponges, synthetic sponges, polymeric netted meshes, and the like.
Accordingly, it is an object of this invention to provide personal cleansing compositions providing improved lathering and conditioning.
Another object of the present invention is to provide improved personal cleansing compositions comprising a nonionic or anionic polymer, a surfactant system and a minimum amount of a phase separation initiator.
One other object of the present invention is to provide personal cleaning compositions which exist as an emulsion comprising a polymer concentrated aqueous phase in an aqueous surfactant phase.
Still another object of the present invention is to provide personal cleansing compositions which can comprise lower or reduced levels of surfactant.
Another object of the present invention is to provide all in one shampoo plus conditioner compositions which can provide excellent cleaning performance and improved levels of conditioning while minimizing any adverse side effects associated with build-up due to the use of excess conditioning agent.
It is also an object of this invention to provide a method for cleaning and conditioning the hair and skin which can provide excellent cleaning in combination with improved conditioning.
These and other objects will become readily apparent from the detailed description which follows.